1. Filed of the Invention
The invention relates to a swing drive mechanism, and more particularly to a swing drive mechanism for electric cradles.
2. Description of the Related Art
When a cradle having a pendulum is in use, the pendulum of the cradle is required to swing stably without wobbling.
Currently, most of swing drive mechanisms for electrical baby cradles are driven by an electromagnet attracting a heavy block, that is, the swing drive mechanisms are driven by a counterforce. During the driving process, the energy output is finished at the moment the electromagnet attracts the heavy block. The force cannot be increased gradually, thereby resulting in an instantaneously irregular wobbling, irregular swing amplitude, and unstable feeling for infants. Furthermore, by the driving mode, the natural frequency of the baby cradles cannot be detected, and thus a resonance between the external force frequency and the natural frequency cannot be formed. Thus, the driving by the electromagnet attracting heavy block has high energy consumption, small and irregular swing amplitude, high production and material costs.